Managers spend nearly 17% of their working hours dealing with poor performers, according to a report from staffing firm Robert Half International. That’s basically a full day a week that could have been spent being productive.

And sucking up supervisors’ time isn’t the only downside to subpar workers, according to the report. Of the more than 1,400 chief financial officers interviewed by Robert Half, 95% said laggards can bring down office spirits.

“Bad hires are costly, not just for the drain they place on the budget but also in terms of lost morale, productivity and time,” Max Messmer, chief executive of Robert Half, said in a statement.